Not Applicable
1. Field of Invention
This invention relates to stabilizing systems for jet-propelled watercraft.
2. Description of Prior Art
Jet-propelled watercraft, lacking the stabilizing force of a propeller in the water, are imprecise in handling, especially when turning. Driving fast can be sketchy and erratic, and hard turns result in sliding and spin-outs, which not only stop forward progress, but can throw the driver and passengers off the boat and cause bodily injury.
One previous attempt to improve the handling of jet-propelled watercraft was to modify the drive plate of the watercraft. One variation of this is U.S. Pat. No. RE35,351, inventor Robert D. Morgan. The drive plate is the center part of the bottom at the stem (back) of the watercraft, and the modifying effort consists of creating longitudinal grooves in the drive plate, to encourage the jet-propelled watercraft to continue in its course. The effects, if any, are minimal.
Another gadget designed to provide control to jet-propelled watercraft, is the so-called xe2x80x9cstabilizerxe2x80x9d. These stabilizers consist of two blocks of plastic, about five centimeters wide, eight centimeters tall, and up to 600 centimeters long, which mount longitudinally to the sides of the boat towards the stem. These little units project their two-inch width horizontally, creating two mini platforms that help keep the boat from tipping from side to side at speed.
Rather than helping the handling, these xe2x80x9cstabilizersxe2x80x9d serve as xe2x80x9ctraining wheelsxe2x80x9d, keeping the watercraft a little more stable, at the loss of fine control and sensitivity. As far as affecting the fuming characteristics, their effect is negligible.
The other method currently in use to improve jet-propelled watercraft""s handling is the use of sponsors. Sponsors are trapezoidal plates of plastic, five to eight centimeters tall by up to about 600 centimeters long, which mount longitudinally on each side of the boat, toward the stem. Rather than extending their width horizontally as the xe2x80x9cstabilizersxe2x80x9d do, sponsors project their width vertically. Their long edges in the water help give the watercraft some stability in the straights, and a little extra bite in the turns. However, the sponsors"" inexact placement, incorrect trim angles, and shallow depth keep them from being a real handling solution, and their straight, longitudinal edges provide a clumsy, inexact turning fulcrum.
A couple of inventions refine the sponson concept, U.S. Pat. No. 5,611,215, by Lloyd J. Stables, and U.S. Pat. No. 6,041,727, by Hisato Yamada, Mitsuhisa Hirano, and Yasukazu Kojima, but neither one addresses the sponsons"" built-in limitations of insufficient height, incorrect angle of attack, and inefficient and crude shape.
Several objects and advantages of the jet-propelled watercraft stabilizing system described in my above patent are:
a. To provide a jet-propelled watercraft stabilizing system which enables the watercraft to drive accurately in a straight line, and respond predictably to the driver""s steering inputs.
b. To provide a jet-propelled watercraft stabilizing system that allows the driver to make severe turns with control and precision.
Further objects and advantages are to provide a jet-propelled watercraft stabilizing system, which, through increasing the driver""s level of control, makes jet-propelled watercraft safer and more fun to use.
The invention comprises a set of fins, and their trim blocks, which point the fins to the correct direction and angle.